Filament mount



April 18, 1944; P. o. CARTUN 2,347,028

PILAMENT MOUNT Filed Sept. 23, 1942 Invewtor:

PauL O.C6T"1TUT1,

His A't't'ovneg.

Patented Apr. 18, 1944 Paul 0. Cartl ln, or to General of New York Cleveland Heights, Ohio, assign- Eleetric Company, a corporation Application September 23, 1942 ,'S'ei-ial No. 459,454

5 Claims.

This invention relates to filament mounts for electric lamps and the like. The invention affords a simple and rugged mount that is easy and economical to manufacture, and can be constructed to stand vibration especially well. In suitable forms of construction, such as here illustrated, the invention is specially adaptable and advantageous for lamps of relatively low wattage and candlepower. Other features and advantages of the invention will become apparent from the description of species or forms of embodiment, and from the drawing,

, In the drawing, Fig. 1 is an elevation of a lamp with a mount embodying the invention in one form, a portion of its envelope or bulb wall being broken away; Fig, 2 is a generally similar view illustrating another form of mount embodying the invention; and Fig. 3 is a similar view of a mount illustrating yet another modification.

The drawing illustrates an incandescent lamp having an ordinary type of bulb or envelope III that includes an inward extending hollow vitreous stem II. Current lead-wires I3, I3 inside the glass stem II enter the bulb I through the seal or press I4 at the inner end of the stem. As here shown, the stem II has a vitreous pedestal extension or arbor I5 inward beyond the seal I4, in the form of a glass rod that is preferably coaxially aligned with the stem. The current leads I 3, I3 extend from the stem II and its seal I4 inward alongside the pedestal I5 and beyond its inner end I6, and may be bent outward at l1, IT to diverge from one another and from the pedestal.

Between the inner ends of the leads I3, I3 is connected the filament 20. Besides end segments 2|, 2| adjacent the leads I3, I3, which are shown as helically coiled, the filament 20 includes an intermediate segment 22 which extends laterally from the straight but coiled segments 2|, 2| and is bent into a V or hairpin loop, but is shown as uncoiled, This intermediate uncoiled segment extends to the pedestal l 5 and is anchored thereto by having its bight or bend embedded and sealed in the rounded end of this pedestal, as by fusion of the glass at I6. In a word, the filament 20 is connected between the ends of the leads I3, l3 and is intermediately embedded and anchored in the pedestal end at I6,

As shown in Fig. l, the arrangement and the lengths of the pedestal [5, leads [3, I3, and filament segments 2 I, 22, 2I are such that these parts all lie in one plane extending through the axis of the stem II, and the divergent portions of the leads I3, I3 and the filament segments 2|, 2| lie on the sides of an imaginary diamond that is substantially a square, while the axis of the hairpin 22 lies' on an upright diagonal of the diamond, in line with the axes of the pedestal I5 and of the stem II. However, it will be understood that the shape of the filament and the arrangement or number of segments can be varied. For example, Fig. 2 shows a mount in which the parts are so proportioned that the straight but coiled filament segments 2'I,2I adjacent the leads I3, I3 lie horizontal and directly in line with one another-so that they might be regarded as in efiect one divided segment -while the intermediate laterally extending bent or V-segment 22 is a very narrow hairpin loop. A so, the leads I 3, I 3 are shown in Fig. 2 as bent and diverging outward from their very emergence at the stem seal M", instead of lying parallel with one another up to the level of the inner pedestal end, as in: Fig. 1. Here, again, the filament extends and is connect ed across between the leads I3, I3, and is intermediately embedded and anchored in the pedestal end I6.

When the filament 20 is made of suitable nonsag tungsten wire, the mount shown provides thoroughly adequate support of the filament due to the fixity of the leads I3, I3 in the stem I 4 and of the hairpin loop 22 in the pedestal I5 at I6. At the same time, the hairpin or V-loop 22 and the coils 2|, 2| provide and permit sufficient resilience and elastic fiexure to accommodate vibration or shock without localized stress or deformation at any point, such as might result in rupture of the filament. Furthermore, there is no possibility of immobilization of the filament midway between the leads I3, I3, as might happen in the case of a more single straight coil con nected between the leads and intermediately supported by a laterally extending anchor wire embracing it at mid-length and mounted in the pedestal, owing to welding or sticking of the filament coil to the surrounding eye of the support wire, Another advantage of the mount, indeed, lies in dispensing with any intermediate anchor wire support or the like.

I Fig. 3 illustrates another form of construction which not only dispenses with any intermediate anchor wire for the filament 200;, but allows the latter to have a simple form that is very easy to make commercially. The distinctive feature of this filament 20a is that its intermediate uncoiled segment 22a is not bent like those in Figs. 1 and 2, but this is straight and relatively short, and is axially in line with both the coiled segments 2i, 2|. Accordingly, the pedestal rod or arbor l extends inward from the stem H substantially into line with the inner ends of the lead wires [3a, I311. The filament 20a extends and is connected substantially straight across between the lead wires 13a, l3a, and is intermediately embedded and thus anchored in the pedestal end at IS. The arrangement of the lead wires l3a, l3a is also different from those in Figs. 1 and-2: i. e., they are bent apart to diverge pronouncedly from the stem H, and are then bent toward one another at Ha, Ha so as to lie substantially parallel right to their ends to which the straight ends of the filament coils 2|, 2| are welded.

While this Fig. 3 form of construtcion is not so especially adapted to stand severe vibration or shock as are those in Figs. 1 and 2, it is very suitable for many lamps that are used in services where vibration or shock is not seriously felt.

It is to be understood that in practice the segments 22 and 220: of Figs. 1, 2, and 3 which have been described as "uncoiled may be pro duced either by leaving a length of the filament wire without coiling, or by coiling the whole length of wire for the filament 20 and afterward pulling the portion 22 or 22a out straight,-

or nearly straight, before bending it hairpinwise, if it is so bent.

In order to dispense with repetitive description, various parts and features in Figs. 2 and 3 are marked with the same reference characters as their homologues in Fig. 1, a distinctive letter being added where such distinctionseems necessary. g

What L claim as new and desire to secure by Letters Patent of the United States is:

1. Anelectric lamp mount comprising a vitreous stem and pedestal structure, lead wires extending inward from the stem alongside the pedestal and diverging outward therefrom for at leasta part of their length, and a filament connected between said lead wires comprising coiled segments adjacent the lead wires and an integral intermediate uncoiled segment sealed and embedded directly in the vitreous end of said pedestal.

2. An electric lamp mount comprising a vitre ous stem and pedestal structure, lead wires extending inward from the stem at opposite sides of the pedestal, with their inner ends substantially in line with that of the pedestal, and a filament extending and connected substantially straight across between the lead wires, and having an integral intermediate portion thereof sealed and embedded directly in the vitreous end of said pedestal.

3. An electric lamp mount comprising a vitreous stem and pedestal structure, lead wires extending inward from the stem alongside the pedestal, and a filament connected between said lead wires comprising segments adjacent the lead wires and an integral intermediate bent segment extending laterallyfrom the first-mentioned segments and anchored to said pedestal.

4. An electric lamp mount comprising a vit reous stem and pedestal structure, lead wires extending inward from the stem alongside and beyond said pedestal, and diverging outward from one another, and a filament connected between said lead wires comprising coiled segments adjacent the lead wires and an integral intermediate bent segment extending back to said pedes tal and anchored thereto.

5. An electric lamp mount comprising a vitreous stem and pedestal structure, lead wires extending inward from the stem alongside and beyond said pedestal, and a filament connected between said lead wires comprising coiled segments adjacent the lead wires and an integral intermediate uncoiled hairpin segment extending back to said pedestal and having its bend sealed and embedded directly in the vitreous material thereof.

PAUL O. CARTUN. 

